/* 
 *  Copyright (c) 2011, Michael Bedward. All rights reserved. 
 *   
 *  Redistribution and use in source and binary forms, with or without modification, 
 *  are permitted provided that the following conditions are met: 
 *   
 *  - Redistributions of source code must retain the above copyright notice, this  
 *    list of conditions and the following disclaimer. 
 *   
 *  - Redistributions in binary form must reproduce the above copyright notice, this 
 *    list of conditions and the following disclaimer in the documentation and/or 
 *    other materials provided with the distribution.   
 *   
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
 *  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 *  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR 
 *  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
 *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 
 *  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */   

package org.jaitools.jiffle.runtime;

import java.awt.Point;
import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;

/**
 * Wraps an AffineTransform object for use as a Jiffle {@link CoordinateTransform}.
 *
 * @author Michael Bedward
 * @since 0.1
 * @version $Id$
 */
public class AffineCoordinateTransform implements CoordinateTransform {
    private final AffineTransform affine;
    private Point2D p2D;

    /**
     * Creates a new instance to wrap the given {@code AffineTransform}. If
     * {@code tr} is {@code null} an identity transform will be used. The
     * input transform is copied.
     * 
     * @param affine the transform
     */
    public AffineCoordinateTransform(AffineTransform affine) {
        this.affine = affine == null ? new AffineTransform() : new AffineTransform(affine);
        p2D = new Point2D.Double();
    }

    /**
     * {@inheritDoc}
     */
    public Point worldToImage(double x, double y, Point p) {
        p2D.setLocation(x, y);
        affine.transform(p2D, p2D);
        
        if (p != null) {
            p.x = (int) Math.round(p2D.getX());
            p.y = (int) Math.round(p2D.getY());
        } else {
            p = new Point((int) Math.round(p2D.getX()), (int) Math.round(p2D.getY()));
        }
        
        return p;
    }
    
}
